The present invention relates generally to the harvesting of grasses. Specifically, the present invention relates to the harvesting of grass seeds while minimizing damage to the standing grass from which the seed is harvested.
The selection of crops for propagation has historically been approached in myriad ways, many of which have been less than scientific. For example, early settlers of the western regions of the United States would often plant the same feed crops that they knew to be successful in their native lands. Unfortunately for such settlers, the climatic conditions and precipitation encountered in places like eastern Montana are radically different from those present in western Europe, frequently leading to disappointment or disaster for the unwary homesteader.
More recently, attention has been directed to grasses and other vegetation that is native to the region of interest or, alternatively, native to regions with similar growing conditions. This has led to growing interest in harvesting the seeds of such plants, frequently grasses, both for feed crops and for restoration of native prairie.
As has been recognized in the art, many varieties of grass seed are difficult to harvest. Such factors as small seed size, light weight of the seeds, the presence of chaff material associated with the seeds, loose attachment of the seed to the plant, variable seed head height, varying rates of seed maturation, and weeds in the grass crop, all contribute to the problems in harvesting grass seed.
It has been further recognized that conventional swathing and combining equipment designed to cut, swath, thresh and clean cereal grain crops is unsuitable for harvesting grass seed. Such equipment cannot selectively recover the mature seeds from the grass plant, since the entire crop must be cut at one time. Only the seeds which are mature at that time are useful. A considerable amount of the mature grass seed is lost in this harvesting procedure, both from shattering of the seed heads by the wind, from impacting of the seed head by the swather reel""s bats, and by falling out of the swath left to dry in the field. Also, the late-maturing seeds are effectively lost.
The harvesting of such crops has been the subject of several patents. For example, U.S. Pat. No. 5,974,772 to Chuksin et al. is directed to a harvester intended to reduce crop wastage and to simplify the design of the combing unit. The essence of the invention lies in the fact that in the combing unit, the teeth of the working combing element are arranged in rows in the direction of travel, and the upper rim of the front wall of the receiving chamber takes the form of resilient teeth whose ends are located between the lateral edges of the teeth of the working combing element; the angle of inclination of the front wall of the receiving chamber to the horizontal plane is greater than the natural slope angle of a heap of cereal, leguminous crops and grass seeds
In another example, U.S. Pat. No. 4,951,453 to Klinner shows an apparatus for harvesting crop including a rotor mounted on a movable frame and carrying a succession of transverse combs, each formed of an array of outwardly projecting teeth traverse to the direction of movement of the apparatus through the crop. Each tooth is pointed with side edges diverging away from the distal tip of the tooth. The rotor rotates in the overshot mode and the combs intrude into the crop and gather crop stems between adjacent pairs of teeth and detach grain and grain heads, or other required crop parts, by rubbing or breaking the parts free from the stems. The junction of adjacent teeth preferably has an enlarged aperture to assist stripping and to allow withdrawal of stripped stems. In other embodiments, the teeth may be replaced by a brush-like structure or by rods or other crop engaging elements, backed by plain transverse ribs for collecting and conveying detached crop parts.
U.S. Pat. No. 4,738,087 to Lundahl discusses a mobile vehicle with a forward vertically adjustable header that includes a mechanism for stripping grain from a standing crop as the machine advances while leaving the stem of the crop attached to the soil. The stripping mechanism including a pair of axially transverse vertically offset brush-type rotors having randomly spaced radial bristles, the upper rotor being disposed slightly forwardly of the lower and being driven so that its lower surface moves rearwardly in close proximity to the rearwardly moving upper surface of the lower roller that is driven in the opposite direction from the first rotor. The grain heads on most of the standing crop are disposed between the axes of the rotors, and the grain is stripped as the heads move into the bite between the rotors. A front blower directs a stream of air toward the bite and a rear blower directs a stream of air upwardly to the rear of the lower rotor, to create a lower pressure zone behind the rotors that assist the feeding of stripping material to a collector bin on the vehicle.
U.S. Pat. No. 4,455,814 to Kienholz is directed to a seed harvester for harvesting seeds from a standing crop without cutting the crop. The harvester is particularly designed for harvesting grass seed. The harvester includes a header assembly for stripping from the crop, and a seed separator for drawing the seeds from the header assembly in an air stream and for separating the seeds from the air stream. The header assembly includes a frame assembly having a transverse inlet which communicates with the seed separator. An endless revolving stripping surface is mounted across this transverse opening to contact the seed heads of the crop and strip the mature seeds from the crop. A rotating reel is mounted to rotate parallel to, and above and forwardly of, the seed stripping surface. On rotation, the reel guides the crop into contact with the seed stripping surface and holds it there for a time to permit the seed stripping surface to remove mature seeds from the crop. The seed separator includes a duct, curved between its ends. The duct inlet communicates with the transverse inlet of the header assembly. A blower is provided at the duct outlet to draw seeds in an air stream, from the header assembly and through the duct. Baffles are provided across the curved duct section which, together with the curve in the duct, cause the seeds to move outwardly toward the outer wall of the curved duct section. This achieves partial separation of the seeds from the air stream. To achieve the remainder of the separation, the seed separator includes a seed withdrawal duct in the outer wall of the curved duct section, and a sealed container at the end of the seed withdrawal duct. Air is drawn through the container and the seed withdrawal duct, preferably by the blower, to carry the seeds in an air stream into the container.
U.S. Pat. No. 4,373,322 to Beisel shows a seed harvester including an elongated hollow housing adapted for support from front loader bucket arms mounted on a tractor with the housing extending transversely of the forward end of the tractor. The housing includes an inlet which opens forwardly and downwardly and in which a rotary brush is mounted for advancing against the upper seed bearing ends of grasses. The brush is driven in a direction wherein the lower marginal portion thereof moves forwardly and the brush is effective to strip the seeds from the upper ends of tall grasses and to convey the stripped seeds into the housing where they are separated from the air flow moving through the housing by centrifugal force and collected in a seed collection point from which the seeds are subsequently removed.
While each of these patented devices offers some advantages over conventional swathing and combining equipment, it can be seen that the need exists for a simple, inexpensive, harvester that efficiently harvests seeds from standing crops while leaving unharmed the plants from which the seeds are harvested.
These and other objects are achieved by providing a harvester including a brush assembly having a plurality of flexible, radial bristles extending from a central axis of the brush assembly. The brush assembly is adapted and constructed for rotation in a first direction. A comb assembly having a plurality of axially extending combs mounted in a position spaced radially from and parallel to a central axis of the comb assembly is also provided. The comb assembly is adapted and constructed for rotation in a direction opposite to the direction of rotation of the brush assembly. A mounting assembly secures the brush assembly and the comb assembly such that the bristles of the brush assembly come into contact with the combs of the comb assembly when the brush assembly and the comb assembly are rotating.
The brush assembly can be provided as a cylindrical brush member having a multiplicity of elongate flexible plastic bristles, which can be fabricated from nylon. The respective comb members can include a bar element having an outer edge, with a plurality of teeth disposed on the outer edge of the bar element. The comb members can be fabricated from suitable material, such as metal or plastic.
A rotation assembly can be secured to the mounting assembly to selectively impart rotation to the brush assembly and the comb assembly. In an embodiment, the rotation assembly is adapted and constructed to impart a faster speed of rotation to the brush assembly than to the comb assembly. The rotation assembly can include at least one orbital hydraulic motor.
The mounting assembly can be provided with a housing member at least partially enclosing the brush member. An exhaust fan assembly can be secured to the housing member to create and maintain negative air pressure in the housing member. The housing member can further define an accumulation chamber adjacent to the brush assembly. A viewing window can provide visual access to the interior of the accumulation chamber. The mounting assembly can include at least one mount to selectively secure the harvester to a vehicle.
The comb assembly can further include a plurality of bat members, corresponding in number to the comb members, mounted between and parallel to the comb members.
A wind screen can be provided on the mounting assembly and at least partially surrounding the comb assembly. The wind screen can include a plurality of flexible flaps secured to a bracket extending from the mounting assembly.
A method of harvesting of grass seeds while minimizing damage to the standing grass from which the seed is harvested is also disclosed. In a first step, a brush assembly having a plurality of flexible, radial bristles extending from a central axis of the brush assembly is provided. A comb assembly having a plurality of axially extending combs mounted in a position spaced radially from and parallel to a central axis of the comb assembly is also provided. The brush assembly and the comb assembly are rotated in opposite directions, then brought into contact with a grass crop to be harvested. The brush assembly and the comb assembly are rotated such that the bristles of the brush assembly come into contact with the combs of the comb assembly when the brush assembly and the comb assembly are rotating, whereby the seed-bearing heads of the standing grass are grasped between the rotating bristles of the brush assembly and the rotating combs of the comb assembly, thereby stripping only mature seeds from the standing grass. The brush assembly can be rotated at a speed of rotation higher than that of a speed of rotation of comb assembly.